diff options
Diffstat (limited to 'debian/patches-rt/0024-serial-digicolor-Use-port-lock-wrappers.patch')
| -rw-r--r-- | debian/patches-rt/0024-serial-digicolor-Use-port-lock-wrappers.patch | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/debian/patches-rt/0024-serial-digicolor-Use-port-lock-wrappers.patch b/debian/patches-rt/0024-serial-digicolor-Use-port-lock-wrappers.patch new file mode 100644 index 000000000..2a3aa5c9a --- /dev/null +++ b/debian/patches-rt/0024-serial-digicolor-Use-port-lock-wrappers.patch @@ -0,0 +1,113 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:43:41 +0206 +Subject: [PATCH 024/134] serial: digicolor: Use port lock wrappers +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz + +When a serial port is used for kernel console output, then all +modifications to the UART registers which are done from other contexts, +e.g. getty, termios, are interference points for the kernel console. + +So far this has been ignored and the printk output is based on the +principle of hope. The rework of the console infrastructure which aims to +support threaded and atomic consoles, requires to mark sections which +modify the UART registers as unsafe. This allows the atomic write function +to make informed decisions and eventually to restore operational state. It +also allows to prevent the regular UART code from modifying UART registers +while printk output is in progress. + +All modifications of UART registers are guarded by the UART port lock, +which provides an obvious synchronization point with the console +infrastructure. + +To avoid adding this functionality to all UART drivers, wrap the +spin_[un]lock*() invocations for uart_port::lock into helper functions +which just contain the spin_[un]lock*() invocations for now. In a +subsequent step these helpers will gain the console synchronization +mechanisms. + +Converted with coccinelle. No functional change. + +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +Acked-by: Baruch Siach <baruch@tkos.co.il> +Signed-off-by: John Ogness <john.ogness@linutronix.de> +Link: https://lore.kernel.org/r/20230914183831.587273-25-john.ogness@linutronix.de +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + drivers/tty/serial/digicolor-usart.c | 18 +++++++++--------- + 1 file changed, 9 insertions(+), 9 deletions(-) + +--- a/drivers/tty/serial/digicolor-usart.c ++++ b/drivers/tty/serial/digicolor-usart.c +@@ -133,7 +133,7 @@ static void digicolor_uart_rx(struct uar + { + unsigned long flags; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + while (1) { + u8 status, ch, ch_flag; +@@ -172,7 +172,7 @@ static void digicolor_uart_rx(struct uar + ch_flag); + } + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + tty_flip_buffer_push(&port->state->port); + } +@@ -185,7 +185,7 @@ static void digicolor_uart_tx(struct uar + if (digicolor_uart_tx_full(port)) + return; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + if (port->x_char) { + writeb_relaxed(port->x_char, port->membase + UA_EMI_REC); +@@ -211,7 +211,7 @@ static void digicolor_uart_tx(struct uar + uart_write_wakeup(port); + + out: +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static irqreturn_t digicolor_uart_int(int irq, void *dev_id) +@@ -333,7 +333,7 @@ static void digicolor_uart_set_termios(s + port->ignore_status_mask |= UA_STATUS_OVERRUN_ERR + | UA_STATUS_PARITY_ERR | UA_STATUS_FRAME_ERR; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + uart_update_timeout(port, termios->c_cflag, baud); + +@@ -341,7 +341,7 @@ static void digicolor_uart_set_termios(s + writeb_relaxed(divisor & 0xff, port->membase + UA_HBAUD_LO); + writeb_relaxed(divisor >> 8, port->membase + UA_HBAUD_HI); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static const char *digicolor_uart_type(struct uart_port *port) +@@ -398,14 +398,14 @@ static void digicolor_uart_console_write + int locked = 1; + + if (oops_in_progress) +- locked = spin_trylock_irqsave(&port->lock, flags); ++ locked = uart_port_trylock_irqsave(port, &flags); + else +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + uart_console_write(port, c, n, digicolor_uart_console_putchar); + + if (locked) +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + /* Wait for transmitter to become empty */ + do { |